Since 1992

How To: Damp Proofing Help and Advice

How To: Damp Proofing

Posted on 05 July, 2021


  • What is Damp?
  • What Causes Damp?
  • What Are The Signs of Damp?
  • Is Damp The Same A Mold?
  • Why Is Damp Bad For A Property?
  • Damp Proofing Vs Waterproofing
  • How To Treat Damp?
  • How to Damp Proof A Wall
  • How to Damp Proof A Cellar
  • Damp Proofing Floors

What is Damp?

Damp is the presence of unwanted moisture and condensation in a property where it shouldn’t be, often seen in walls, ceilings and window sills.

What Causes Damp?

Poor building maintenance and lack of damp proofing in a property can cause damp. Leaking pipes or rain seeping into the property can also lead to damp. If a newly built property has not been left to dry out properly, this can also cause damp.

What Are The Signs Of Damp?

There are a number of signs when it comes to spotting damp, including a musty smell, black spots, dry rot and wet rot.

Is Damp The Same As Mold?

Mold is often the result of damp but both have similar characteristics and the signs of mold include dark patches on walls and ceilings as well as a musty smell.

Why Is Damp Bad For A Property?

Damp can cause damage to a property’s infrastructure. This includes rotting and deteriorating wood. Damp can also affect your health, potentially leading to respiratory problems.

Damp Proofing Vs Waterproofing

You may think that damp proofing and waterproofing are the same thing, but in fact, they are very different. Damp proofing helps to keep soil moisture away whilst waterproofing is designed to prevent moisture and water.

The Different Types Of Damp

There are a number of different types of damp. Knowing the kind of damp you have will help you figure out how to fix the issue. The following are the three main types of damp often found on a property.

Condensation – This occurs when excess water vapour sits on cold surfaces such as windows and walls. This is often caused by lack of ventilation.

Penetrating – This is often found when water from the exterior of a property penetrates to the substrate. This can be due to issues with the building’s joints or roofing. Poor pointing or blocked guttering can also lead to penetrating damp.

Rising – Many properties experience rising damp, which is commonly caused if there is no damp proof course present on the property. It can also occur if the damp proofing used has failed.

How To Treat Damp?

Below is a guide on how to fix damp in a property and prevent it from reappearing. Damp proofing is essential to maintaining a building and its structure.

Please Note: If the area of mold is larger than 1 metre squared, do not attempt to remove this yourself and contact a professional. You should also seek professional help if the mold has been caused by contaminated water.

Tools Needed

  • Protective Clothing (goggles, rubber gloves, face mask)
  • Plastic bag
  • Bucket
  • Washing up liquid
  • Cloths
  • Wet Wipes
  • Vacuum Cleaner

Step 1 –
Put on protective clothing including goggles, rubber gloves and a face mask and ventilate the room by opening windows. Keep doors closed to prevent the spread of spores to other rooms in the property.

Step 2 –
Remove any items from the room that have become mouldy such as soft furnishings and clothes. These should be professionally cleaned to remove the mold. Shampoo the furnishings and dry clean the clothes.

Step 3 –
Mix water and washing up liquid in a bucket. Dip a cloth into the water and wipe the mold from the wall. Try not to scrub or brush back and forth as this can release mold spores.

Step 4 –
Use a dry cloth to wipe dry the walls then put the cloths in a plastic bag and throw away.

Step 5 –
Once the room has dried, use wet wipes or a vacuum cleaner to thoroughly clean the room afterwards.

Once you have removed the damp, there are a number of ways to help prevent damp from reoccurring.

Damp Proofing Options

What are options are available when it comes to preventing damp? There are a number of different ways to damp proof your property. Below are some of the most common.

Damp Proof Membrane

Damp proof membrane is a material that is often made from polyethylene and comes in the form of a sheet. It is laid underneath the floor or within the wall and helps moisture to evaporate, preventing the damp from transferring to the interior of the property. Damp proof membrane is extremely flexible, meaning it can withstand movement from the structure of the building.

Damp Proof Paint

Damp proof paint is an option for preventing damp and is commonly applied to interior walls to help decrease the chances of the damp resurfacing. Damp proof paint contains a polymer which blocks water and inhibits mould growth and can be applied to brickwork, plaster, concrete and cement.


Tanking, also known as cementitious tanking or tanking slurry, is another form of damp proofing. It helps block water by forming a barrier to the property structure. This prevents damp from seeping into walls and floors. Upon application, the tanking hardens and creates a vapour permeable substance.


Another option for damp proofing is Epoxy. Liquid Epoxy is an effective waterproof barrier for concrete flooring. This is commonly used just before the installation of new floors and contains chemicals that reduce water vapour from passing through and tolerates moisture in concrete flooring.


You can use damp proof membranes to damp proof walls. It is vital that the membrane is installed properly to prevent water ingress and should be used alongside a damp proof course on the external walls.

  • Firstly remove the plaster and any wall surfaces that are deteriorating.
  • Cut the damp proof membrane to the size that is required.
  • Place the membrane on the wall and fold the corners.
  • Fix the membrane by drilling it to the wall and make sure it is fitted tight
  • Apply a wall finish to the membrane

As well as damp proof membrane, you can also use damp proof paint or a liquid epoxy to prevent damp.


Installing a tanking system is an effective way to damp proof a cellar and provide a waterproof coating for walls and floors. You can also install a cavity drainage system to damp proof a cellar. To tank a cellar, carry out the following steps:

  • Remove any plaster or render from the walls as well as other coatings such as paints and bitumens. Remove mortar joints too and make sure walls are dust free.
  • Repair any existing cracks or holes.
  • Coat the walls and flooring, creating a waterproof box. Create a fillet joint where the wall meets the flooring.
  • Use a product such as Everbuild Tanking Slurry to tank the cellar. Make sure to properly follow the manufacturer’s instructions when applying the slurry. Always wear protective clothing and avoid contact with skin.


It is common to see damp rise up through floors if the membrane has not worked at preventing the damp. If carpets become damp or wooden floors start to warp, you need to install damp proofing for your flooring.

  • For concrete floors, start by digging up the old flooring and install a damp proof membrane with lap up edges then replace the concrete slabs.
  • If using epoxy, firstly prepare the concrete surface and remove previous coatings, debris and surface water.
  • Paint the epoxy onto the floor, applying 2 to 3 coats. Allow each coat to dry before applying the next coat.
  • If you are laying down laminate flooring, be sure to install the damp proof membrane underneath the flooring, with the insulation layer being above the DPM.

Preventing Damp

To help prevent damp, keep the home warm during the colder months of the year. The heat will help to maintain an insulated property that is less likely to suffer from condensation. Make sure to put radiators on if the temperature drops to ensure a properly warmed home.

Keeping on top of outdoor maintenance will also help prevent damp. Make sure gutters are working properly and are free from debris. If you spot holes or breakage in your guttering and downpipes, be sure to fix and replace this as soon as possible to ensure rainwater is diverted away from the property. Check out our blog post on how to fit guttering for info on fixing gutters.

A well-ventilated home will also help prevent damp. Having proper ventilation around the property will provide an escape for moisture and help minimise condensation. Installing extractor fans in places like bathrooms and kitchens can help with ventilation. You could also try keeping windows open after showering or cooking to let steam escape and prevent damp air from settling into the walls and ceiling. Dehumidifier machines can also help remove excess moisture from the air.

Another way to reduce the chances of damp is to improve air circulation. Position furniture a few centimetres from the walls to help with this. 

Waterproofing, damp proofing and weather-proofing your property can help to prevent damp from occurring in the property and can help protect your home from further damage. Using products such as Everbuild Black Jack DPM or damp proof membrane. You will find a range of damp proofing and roof waterproofing products at BC Profiles to help with preventing damp in the home.

Share this article

We use ‘strictly necessary’ cookies (or similar small data files) to provide you with the best possible website user experience. By clicking “ACCEPT”, you agree to such purposes. You can find out more and learn about how to withdraw your consent at any time, by clicking here: Privacy & Cookies Policy.

Cookie preferences

Google Analytics

User Experience (Strictly Necessary)

The website is built using Shopify. Shopify’s default cookies don’t collect any personal or sensitive information or IP addresses. The information that they store is not sent to any third parties, and they are used only to communicate with Shopify for the purposes of user authentication, form validation/security, and basic web application operations. To learn more, please see our Privacy & Cookies Policy.